You would need a phone that supports bands 1 (Europe's 2100 band), 3 (1800, or DCS), 7 (2600), & 8 (900) in Europe. T-Mobile/MetroPCS exclusive phones are less likely to support these bands for 3G or 4G LTE. It would essentially require a phone that's made for multiple carriers, & list these bands. Luckily, my Samsung Galaxy S6 edge+ supports nearly every band out there, including Band 13 (exclusively a Verizon band on the mainland and Hawaii, though I believe T-Mobile is supporting that band for Canadian carriers more than with Verizon), 17 for areas where T-Mobile still has a roaming agreement with AT&T, and a list of others (too many to list).